1 //===-- asan_rtl.cpp ------------------------------------------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file is a part of AddressSanitizer, an address sanity checker.
11 // Main file of the ASan run-time library.
12 //===----------------------------------------------------------------------===//
14 #include "asan_activation.h"
15 #include "asan_allocator.h"
16 #include "asan_fake_stack.h"
17 #include "asan_interceptors.h"
18 #include "asan_interface_internal.h"
19 #include "asan_internal.h"
20 #include "asan_mapping.h"
21 #include "asan_poisoning.h"
22 #include "asan_report.h"
23 #include "asan_stack.h"
24 #include "asan_stats.h"
25 #include "asan_suppressions.h"
26 #include "asan_thread.h"
27 #include "lsan/lsan_common.h"
28 #include "sanitizer_common/sanitizer_atomic.h"
29 #include "sanitizer_common/sanitizer_flags.h"
30 #include "sanitizer_common/sanitizer_interface_internal.h"
31 #include "sanitizer_common/sanitizer_libc.h"
32 #include "sanitizer_common/sanitizer_symbolizer.h"
33 #include "ubsan/ubsan_init.h"
34 #include "ubsan/ubsan_platform.h"
36 uptr __asan_shadow_memory_dynamic_address
; // Global interface symbol.
37 int __asan_option_detect_stack_use_after_return
; // Global interface symbol.
38 uptr
*__asan_test_only_reported_buggy_pointer
; // Used only for testing asan.
42 uptr AsanMappingProfile
[kAsanMappingProfileSize
];
44 static void AsanDie() {
45 static atomic_uint32_t num_calls
;
46 if (atomic_fetch_add(&num_calls
, 1, memory_order_relaxed
) != 0) {
47 // Don't die twice - run a busy loop.
49 internal_sched_yield();
52 if (common_flags()->print_module_map
>= 1)
54 if (flags()->sleep_before_dying
) {
55 Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying
);
56 SleepForSeconds(flags()->sleep_before_dying
);
58 if (flags()->unmap_shadow_on_exit
) {
60 UnmapOrDie((void*)kLowShadowBeg
, kMidMemBeg
- kLowShadowBeg
);
61 UnmapOrDie((void*)kMidMemEnd
, kHighShadowEnd
- kMidMemEnd
);
64 UnmapOrDie((void*)kLowShadowBeg
, kHighShadowEnd
- kLowShadowBeg
);
69 static void CheckUnwind() {
70 GET_STACK_TRACE(kStackTraceMax
, common_flags()->fast_unwind_on_check
);
74 // -------------------------- Globals --------------------- {{{1
76 bool asan_init_is_running
;
78 #if !ASAN_FIXED_MAPPING
79 uptr kHighMemEnd
, kMidMemBeg
, kMidMemEnd
;
82 // -------------------------- Misc ---------------- {{{1
83 void ShowStatsAndAbort() {
84 __asan_print_accumulated_stats();
89 static void ReportGenericErrorWrapper(uptr addr
, bool is_write
, int size
,
90 int exp_arg
, bool fatal
) {
92 ReportGenericError(pc
, bp
, sp
, addr
, is_write
, size
, exp_arg
, fatal
);
95 // --------------- LowLevelAllocateCallbac ---------- {{{1
96 static void OnLowLevelAllocate(uptr ptr
, uptr size
) {
97 PoisonShadow(ptr
, size
, kAsanInternalHeapMagic
);
100 // -------------------------- Run-time entry ------------------- {{{1
101 // exported functions
102 #define ASAN_REPORT_ERROR(type, is_write, size) \
103 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
104 void __asan_report_ ## type ## size(uptr addr) { \
105 GET_CALLER_PC_BP_SP; \
106 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true); \
108 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
109 void __asan_report_exp_ ## type ## size(uptr addr, u32 exp) { \
110 GET_CALLER_PC_BP_SP; \
111 ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true); \
113 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
114 void __asan_report_ ## type ## size ## _noabort(uptr addr) { \
115 GET_CALLER_PC_BP_SP; \
116 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false); \
119 ASAN_REPORT_ERROR(load, false, 1)
120 ASAN_REPORT_ERROR(load
, false, 2)
121 ASAN_REPORT_ERROR(load
, false, 4)
122 ASAN_REPORT_ERROR(load
, false, 8)
123 ASAN_REPORT_ERROR(load
, false, 16)
124 ASAN_REPORT_ERROR(store
, true, 1)
125 ASAN_REPORT_ERROR(store
, true, 2)
126 ASAN_REPORT_ERROR(store
, true, 4)
127 ASAN_REPORT_ERROR(store
, true, 8)
128 ASAN_REPORT_ERROR(store
, true, 16)
130 #define ASAN_REPORT_ERROR_N(type, is_write) \
131 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
132 void __asan_report_ ## type ## _n(uptr addr, uptr size) { \
133 GET_CALLER_PC_BP_SP; \
134 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true); \
136 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
137 void __asan_report_exp_ ## type ## _n(uptr addr, uptr size, u32 exp) { \
138 GET_CALLER_PC_BP_SP; \
139 ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true); \
141 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
142 void __asan_report_ ## type ## _n_noabort(uptr addr, uptr size) { \
143 GET_CALLER_PC_BP_SP; \
144 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false); \
147 ASAN_REPORT_ERROR_N(load, false)
148 ASAN_REPORT_ERROR_N(store
, true)
150 #define ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp_arg, fatal) \
151 uptr sp = MEM_TO_SHADOW(addr); \
152 uptr s = size <= ASAN_SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp) \
153 : *reinterpret_cast<u16 *>(sp); \
155 if (UNLIKELY(size >= ASAN_SHADOW_GRANULARITY || \
156 ((s8)((addr & (ASAN_SHADOW_GRANULARITY - 1)) + size - 1)) >= \
158 ReportGenericErrorWrapper(addr, is_write, size, exp_arg, fatal); \
162 #define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size) \
163 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
164 void __asan_##type##size(uptr addr) { \
165 ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, true) \
167 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
168 void __asan_exp_##type##size(uptr addr, u32 exp) { \
169 ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp, true) \
171 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
172 void __asan_##type##size ## _noabort(uptr addr) { \
173 ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, false) \
176 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
177 ASAN_MEMORY_ACCESS_CALLBACK(load
, false, 2)
178 ASAN_MEMORY_ACCESS_CALLBACK(load
, false, 4)
179 ASAN_MEMORY_ACCESS_CALLBACK(load
, false, 8)
180 ASAN_MEMORY_ACCESS_CALLBACK(load
, false, 16)
181 ASAN_MEMORY_ACCESS_CALLBACK(store
, true, 1)
182 ASAN_MEMORY_ACCESS_CALLBACK(store
, true, 2)
183 ASAN_MEMORY_ACCESS_CALLBACK(store
, true, 4)
184 ASAN_MEMORY_ACCESS_CALLBACK(store
, true, 8)
185 ASAN_MEMORY_ACCESS_CALLBACK(store
, true, 16)
188 NOINLINE INTERFACE_ATTRIBUTE
189 void __asan_loadN(uptr addr
, uptr size
) {
190 if (__asan_region_is_poisoned(addr
, size
)) {
192 ReportGenericError(pc
, bp
, sp
, addr
, false, size
, 0, true);
197 NOINLINE INTERFACE_ATTRIBUTE
198 void __asan_exp_loadN(uptr addr
, uptr size
, u32 exp
) {
199 if (__asan_region_is_poisoned(addr
, size
)) {
201 ReportGenericError(pc
, bp
, sp
, addr
, false, size
, exp
, true);
206 NOINLINE INTERFACE_ATTRIBUTE
207 void __asan_loadN_noabort(uptr addr
, uptr size
) {
208 if (__asan_region_is_poisoned(addr
, size
)) {
210 ReportGenericError(pc
, bp
, sp
, addr
, false, size
, 0, false);
215 NOINLINE INTERFACE_ATTRIBUTE
216 void __asan_storeN(uptr addr
, uptr size
) {
217 if (__asan_region_is_poisoned(addr
, size
)) {
219 ReportGenericError(pc
, bp
, sp
, addr
, true, size
, 0, true);
224 NOINLINE INTERFACE_ATTRIBUTE
225 void __asan_exp_storeN(uptr addr
, uptr size
, u32 exp
) {
226 if (__asan_region_is_poisoned(addr
, size
)) {
228 ReportGenericError(pc
, bp
, sp
, addr
, true, size
, exp
, true);
233 NOINLINE INTERFACE_ATTRIBUTE
234 void __asan_storeN_noabort(uptr addr
, uptr size
) {
235 if (__asan_region_is_poisoned(addr
, size
)) {
237 ReportGenericError(pc
, bp
, sp
, addr
, true, size
, 0, false);
241 // Force the linker to keep the symbols for various ASan interface functions.
242 // We want to keep those in the executable in order to let the instrumented
243 // dynamic libraries access the symbol even if it is not used by the executable
244 // itself. This should help if the build system is removing dead code at link
246 static NOINLINE
void force_interface_symbols() {
247 volatile int fake_condition
= 0; // prevent dead condition elimination.
248 // __asan_report_* functions are noreturn, so we need a switch to prevent
249 // the compiler from removing any of them.
251 switch (fake_condition
) {
252 case 1: __asan_report_load1(0); break;
253 case 2: __asan_report_load2(0); break;
254 case 3: __asan_report_load4(0); break;
255 case 4: __asan_report_load8(0); break;
256 case 5: __asan_report_load16(0); break;
257 case 6: __asan_report_load_n(0, 0); break;
258 case 7: __asan_report_store1(0); break;
259 case 8: __asan_report_store2(0); break;
260 case 9: __asan_report_store4(0); break;
261 case 10: __asan_report_store8(0); break;
262 case 11: __asan_report_store16(0); break;
263 case 12: __asan_report_store_n(0, 0); break;
264 case 13: __asan_report_exp_load1(0, 0); break;
265 case 14: __asan_report_exp_load2(0, 0); break;
266 case 15: __asan_report_exp_load4(0, 0); break;
267 case 16: __asan_report_exp_load8(0, 0); break;
268 case 17: __asan_report_exp_load16(0, 0); break;
269 case 18: __asan_report_exp_load_n(0, 0, 0); break;
270 case 19: __asan_report_exp_store1(0, 0); break;
271 case 20: __asan_report_exp_store2(0, 0); break;
272 case 21: __asan_report_exp_store4(0, 0); break;
273 case 22: __asan_report_exp_store8(0, 0); break;
274 case 23: __asan_report_exp_store16(0, 0); break;
275 case 24: __asan_report_exp_store_n(0, 0, 0); break;
276 case 25: __asan_register_globals(nullptr, 0); break;
277 case 26: __asan_unregister_globals(nullptr, 0); break;
278 case 27: __asan_set_death_callback(nullptr); break;
279 case 28: __asan_set_error_report_callback(nullptr); break;
280 case 29: __asan_handle_no_return(); break;
281 case 30: __asan_address_is_poisoned(nullptr); break;
282 case 31: __asan_poison_memory_region(nullptr, 0); break;
283 case 32: __asan_unpoison_memory_region(nullptr, 0); break;
284 case 34: __asan_before_dynamic_init(nullptr); break;
285 case 35: __asan_after_dynamic_init(); break;
286 case 36: __asan_poison_stack_memory(0, 0); break;
287 case 37: __asan_unpoison_stack_memory(0, 0); break;
288 case 38: __asan_region_is_poisoned(0, 0); break;
289 case 39: __asan_describe_address(0); break;
290 case 40: __asan_set_shadow_00(0, 0); break;
291 case 41: __asan_set_shadow_f1(0, 0); break;
292 case 42: __asan_set_shadow_f2(0, 0); break;
293 case 43: __asan_set_shadow_f3(0, 0); break;
294 case 44: __asan_set_shadow_f5(0, 0); break;
295 case 45: __asan_set_shadow_f8(0, 0); break;
300 static void asan_atexit() {
301 Printf("AddressSanitizer exit stats:\n");
302 __asan_print_accumulated_stats();
303 // Print AsanMappingProfile.
304 for (uptr i
= 0; i
< kAsanMappingProfileSize
; i
++) {
305 if (AsanMappingProfile
[i
] == 0) continue;
306 Printf("asan_mapping.h:%zd -- %zd\n", i
, AsanMappingProfile
[i
]);
310 static void InitializeHighMemEnd() {
311 #if !ASAN_FIXED_MAPPING
312 kHighMemEnd
= GetMaxUserVirtualAddress();
313 // Increase kHighMemEnd to make sure it's properly
314 // aligned together with kHighMemBeg:
315 kHighMemEnd
|= (GetMmapGranularity() << ASAN_SHADOW_SCALE
) - 1;
316 #endif // !ASAN_FIXED_MAPPING
317 CHECK_EQ((kHighMemBeg
% GetMmapGranularity()), 0);
320 void PrintAddressSpaceLayout() {
322 Printf("|| `[%p, %p]` || HighMem ||\n",
323 (void*)kHighMemBeg
, (void*)kHighMemEnd
);
324 Printf("|| `[%p, %p]` || HighShadow ||\n",
325 (void*)kHighShadowBeg
, (void*)kHighShadowEnd
);
328 Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
329 (void*)kShadowGap3Beg
, (void*)kShadowGap3End
);
330 Printf("|| `[%p, %p]` || MidMem ||\n",
331 (void*)kMidMemBeg
, (void*)kMidMemEnd
);
332 Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
333 (void*)kShadowGap2Beg
, (void*)kShadowGap2End
);
334 Printf("|| `[%p, %p]` || MidShadow ||\n",
335 (void*)kMidShadowBeg
, (void*)kMidShadowEnd
);
337 Printf("|| `[%p, %p]` || ShadowGap ||\n",
338 (void*)kShadowGapBeg
, (void*)kShadowGapEnd
);
340 Printf("|| `[%p, %p]` || LowShadow ||\n",
341 (void*)kLowShadowBeg
, (void*)kLowShadowEnd
);
342 Printf("|| `[%p, %p]` || LowMem ||\n",
343 (void*)kLowMemBeg
, (void*)kLowMemEnd
);
345 Printf("MemToShadow(shadow): %p %p",
346 (void*)MEM_TO_SHADOW(kLowShadowBeg
),
347 (void*)MEM_TO_SHADOW(kLowShadowEnd
));
350 (void*)MEM_TO_SHADOW(kHighShadowBeg
),
351 (void*)MEM_TO_SHADOW(kHighShadowEnd
));
355 (void*)MEM_TO_SHADOW(kMidShadowBeg
),
356 (void*)MEM_TO_SHADOW(kMidShadowEnd
));
359 Printf("redzone=%zu\n", (uptr
)flags()->redzone
);
360 Printf("max_redzone=%zu\n", (uptr
)flags()->max_redzone
);
361 Printf("quarantine_size_mb=%zuM\n", (uptr
)flags()->quarantine_size_mb
);
362 Printf("thread_local_quarantine_size_kb=%zuK\n",
363 (uptr
)flags()->thread_local_quarantine_size_kb
);
364 Printf("malloc_context_size=%zu\n",
365 (uptr
)common_flags()->malloc_context_size
);
367 Printf("SHADOW_SCALE: %d\n", (int)ASAN_SHADOW_SCALE
);
368 Printf("SHADOW_GRANULARITY: %d\n", (int)ASAN_SHADOW_GRANULARITY
);
369 Printf("SHADOW_OFFSET: 0x%zx\n", (uptr
)ASAN_SHADOW_OFFSET
);
370 CHECK(ASAN_SHADOW_SCALE
>= 3 && ASAN_SHADOW_SCALE
<= 7);
372 CHECK(kMidShadowBeg
> kLowShadowEnd
&&
373 kMidMemBeg
> kMidShadowEnd
&&
374 kHighShadowBeg
> kMidMemEnd
);
377 static void AsanInitInternal() {
378 if (LIKELY(asan_inited
)) return;
379 SanitizerToolName
= "AddressSanitizer";
380 CHECK(!asan_init_is_running
&& "ASan init calls itself!");
381 asan_init_is_running
= true;
385 // Initialize flags. This must be done early, because most of the
386 // initialization steps look at flags().
389 // Stop performing init at this point if we are being loaded via
390 // dlopen() and the platform supports it.
391 if (SANITIZER_SUPPORTS_INIT_FOR_DLOPEN
&& UNLIKELY(HandleDlopenInit())) {
392 asan_init_is_running
= false;
393 VReport(1, "AddressSanitizer init is being performed for dlopen().\n");
397 AsanCheckIncompatibleRT();
398 AsanCheckDynamicRTPrereqs();
399 AvoidCVE_2016_2143();
401 SetCanPoisonMemory(flags()->poison_heap
);
402 SetMallocContextSize(common_flags()->malloc_context_size
);
404 InitializePlatformExceptionHandlers();
406 InitializeHighMemEnd();
408 // Make sure we are not statically linked.
409 AsanDoesNotSupportStaticLinkage();
411 // Install tool-specific callbacks in sanitizer_common.
412 AddDieCallback(AsanDie
);
413 SetCheckUnwindCallback(CheckUnwind
);
414 SetPrintfAndReportCallback(AppendToErrorMessageBuffer
);
416 __sanitizer_set_report_path(common_flags()->log_path
);
418 __asan_option_detect_stack_use_after_return
=
419 flags()->detect_stack_use_after_return
;
421 __sanitizer::InitializePlatformEarly();
423 // Re-exec ourselves if we need to set additional env or command line args.
426 // Setup internal allocator callback.
427 SetLowLevelAllocateMinAlignment(ASAN_SHADOW_GRANULARITY
);
428 SetLowLevelAllocateCallback(OnLowLevelAllocate
);
430 InitializeAsanInterceptors();
433 // Enable system log ("adb logcat") on Android.
434 // Doing this before interceptors are initialized crashes in:
435 // AsanInitInternal -> android_log_write -> __interceptor_strcmp
438 ReplaceSystemMalloc();
440 DisableCoreDumperIfNecessary();
442 InitializeShadowMemory();
444 AsanTSDInit(PlatformTSDDtor
);
445 InstallDeadlySignalHandlers(AsanOnDeadlySignal
);
447 AllocatorOptions allocator_options
;
448 allocator_options
.SetFrom(flags(), common_flags());
449 InitializeAllocator(allocator_options
);
451 if (SANITIZER_START_BACKGROUND_THREAD_IN_ASAN_INTERNAL
)
452 MaybeStartBackgroudThread();
454 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
455 // should be set to 1 prior to initializing the threads.
457 asan_init_is_running
= false;
462 InitializeCoverage(common_flags()->coverage
, common_flags()->coverage_dir
);
464 // Now that ASan runtime is (mostly) initialized, deactivate it if
465 // necessary, so that it can be re-activated when requested.
466 if (flags()->start_deactivated
)
472 // Create main thread.
473 AsanThread
*main_thread
= CreateMainThread();
474 CHECK_EQ(0, main_thread
->tid());
475 force_interface_symbols(); // no-op.
476 SanitizerInitializeUnwinder();
478 if (CAN_SANITIZE_LEAKS
) {
479 __lsan::InitCommonLsan();
480 InstallAtExitCheckLeaks();
484 __ubsan::InitAsPlugin();
487 InitializeSuppressions();
489 if (CAN_SANITIZE_LEAKS
) {
490 // LateInitialize() calls dlsym, which can allocate an error string buffer
491 // in the TLS. Let's ignore the allocation to avoid reporting a leak.
492 __lsan::ScopedInterceptorDisabler disabler
;
493 Symbolizer::LateInitialize();
495 Symbolizer::LateInitialize();
498 VReport(1, "AddressSanitizer Init done\n");
500 if (flags()->sleep_after_init
) {
501 Report("Sleeping for %d second(s)\n", flags()->sleep_after_init
);
502 SleepForSeconds(flags()->sleep_after_init
);
506 // Initialize as requested from some part of ASan runtime library (interceptors,
508 void AsanInitFromRtl() {
513 // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
514 // (and thus normal initializers from .preinit_array or modules haven't run).
516 class AsanInitializer
{
523 static AsanInitializer asan_initializer
;
524 #endif // ASAN_DYNAMIC
526 void UnpoisonStack(uptr bottom
, uptr top
, const char *type
) {
527 static const uptr kMaxExpectedCleanupSize
= 64 << 20; // 64M
528 if (top
- bottom
> kMaxExpectedCleanupSize
) {
529 static bool reported_warning
= false;
530 if (reported_warning
)
532 reported_warning
= true;
534 "WARNING: ASan is ignoring requested __asan_handle_no_return: "
535 "stack type: %s top: %p; bottom %p; size: %p (%zd)\n"
536 "False positive error reports may follow\n"
538 "https://github.com/google/sanitizers/issues/189\n",
539 type
, (void *)top
, (void *)bottom
, (void *)(top
- bottom
),
543 PoisonShadow(bottom
, RoundUpTo(top
- bottom
, ASAN_SHADOW_GRANULARITY
), 0);
546 static void UnpoisonDefaultStack() {
549 if (AsanThread
*curr_thread
= GetCurrentThread()) {
551 const uptr page_size
= GetPageSizeCached();
552 top
= curr_thread
->stack_top();
553 bottom
= ((uptr
)&local_stack
- page_size
) & ~(page_size
- 1);
555 CHECK(!SANITIZER_FUCHSIA
);
556 // If we haven't seen this thread, try asking the OS for stack bounds.
557 uptr tls_addr
, tls_size
, stack_size
;
558 GetThreadStackAndTls(/*main=*/false, &bottom
, &stack_size
, &tls_addr
,
560 top
= bottom
+ stack_size
;
563 UnpoisonStack(bottom
, top
, "default");
566 static void UnpoisonFakeStack() {
567 AsanThread
*curr_thread
= GetCurrentThread();
570 FakeStack
*stack
= curr_thread
->get_fake_stack();
573 stack
->HandleNoReturn();
576 } // namespace __asan
578 // ---------------------- Interface ---------------- {{{1
579 using namespace __asan
;
581 void NOINLINE
__asan_handle_no_return() {
582 if (asan_init_is_running
)
585 if (!PlatformUnpoisonStacks())
586 UnpoisonDefaultStack();
591 extern "C" void *__asan_extra_spill_area() {
592 AsanThread
*t
= GetCurrentThread();
594 return t
->extra_spill_area();
597 void __asan_handle_vfork(void *sp
) {
598 AsanThread
*t
= GetCurrentThread();
600 uptr bottom
= t
->stack_bottom();
601 PoisonShadow(bottom
, (uptr
)sp
- bottom
, 0);
604 void NOINLINE
__asan_set_death_callback(void (*callback
)(void)) {
605 SetUserDieCallback(callback
);
608 // Initialize as requested from instrumented application code.
609 // We use this call as a trigger to wake up ASan from deactivated state.
615 void __asan_version_mismatch_check() {